With the recent growth of digital technologies, various types of electronic devices such as mobile communication terminals, smart phones, tablet personal computers (PCs), notebook computers, wearable devices, digital cameras, personal computers (PCs) or the like are being widely used.
The recent trend is that connection between electronic devices employs cable-less wireless connection in place of cable connection. Also, even in the case of electronic device charging, cable charging is being replaced with wireless charging. For example, in the case of a cable connection scheme, when an electronic device, a docking station, and an external device are all cable-connected with one another, it can cause limitations in connectivity, mobility or operability. Accordingly to this, wireless connection between the devices can provide a convenience of connection between the devices, and can provide a convenience of movement or operation of the devices.